The present invention relates generally to the art of reducing ultraviolet radiation degradation of polycarbonate, and relates more particularly to reducing ultraviolet radiation degradation of polycarbonate which is laminated to polyurethane.
Transparent laminates having a variety of desirable properties may be formed from multiple layers of glass, polycarbonate, polyurethane and other materials. However, it is often necessary to treat the surfaces to be bonded or to apply bonding agents to the interfacial areas to be bonded. In addition, it may be desirable, especially if a polymeric surface is to be exposed, to protect the plastic from weathering and abrasion which can deteriorate its optical quality.
U.S. Pat. No. 3,388,032 to Saunders discloses a multiple laminate produced by preparing a prelaminate of polycarbonate sandwiched between sheets of polyurethane, and then laminating the plastic sandwich to glass. The prelaminate is formed by simply pressing a sheet of polycarbonate between two sheets of polyurethane.
U.S. Pat. No. 3,657,057 to Shorr et al discloses improving the adhesion of a cured sheet of polyurethane to a rigid transparent sheet, such as glass or polycarbonate, by interposing a polymerizable polyurethane resin between the cured polyurethane sheet and the rigid transparent sheet prior to lamination.
U.S. Pat. No. 3,666,614 to Snedeker et al discloses glass-polycarbonate resin laminates wherein the polycarbonate surface may be covered with an abrasion resistant material which is bonded to the polycarbonate using the ethylene-vinyl acetate copolymer of the invention, or any other suitable adhesive.
U.S. Pat. No. 4,204,026 to Le Grand et al discloses a glass-polycarbonate laminate wherein the glass layer is bonded to a polycarbonate layer by means of a bonding system comprised of an aminoalkyl [poly(aryloxysiloxane)] primer and an organopolysiloxane-polycarbonate block copolymer bonding agent. It further discloses that an abrasion resistant coating, such as polyurethane, can be bonded to the polycarbonate during or subsequent to the lamination of the polycarbonate to glass.